This project is designed to identify and understand the role of specific metabolic processes involved in the operation of circadian clocks. Two general approaches are being used. First, we are isolating single gene mutants of Neurospora crassa which have an alteration in the timing mechanism of their circadian rhythm of conidiation and analyzing such mutants genetically, physiologically, and biochemically. Ultimately, we hope to identify the biochemical nature of the lesion in these mutants in order to correlate the clock alterations with specific metabolic changes. Second, we are analyzing the effects on the clock of known biochemical defects in a variety of nutritional and morphological mutants, again with the ultimate goal of correlating specific biochemical lesions with alterations in the clock mechanism.